Here is the information from Ken Wagner in a document released in March 2013:

Any student who in the 2013-14 school year or thereafter, regardless of grade of enrollment, begins his or her first commencement-level math course culminating in a Regents Exam in June 2014 or later must take the New York State CCLS Regents Exam in mathematics that corresponds to that course, as available, and be provided with Common Core instruction. Most typically, this first course will be Algebra I (Common Core). Those students who began or will complete an Integrated Algebra, Geometry, or Algebra 2/Trigonometry course prior to the 2013-14 school year must take the corresponding Regents Exams aligned to the Mathematics Core Curriculum (Revised 2005), while those exams are still being offered. For the June 2014 and August 2014 administrations only, students receiving Algebra I (Common Core) instruction may, at local discretion, take the Regents Examination in Integrated Algebra (2005 Revised) in addition to the Regents Examination in Algebra I (Common Core). If students !take the old Regents Exam in addition to the new Regents Exam, the higher of the two scores may be used for local transcript purposes, and will be used for institutional accountability for the 2013-14 school year results. In addition, such students may meet the mathematics exam requirement for graduation by passing either of these exams. For purposes of APPRs conducted pursuant to Education Law B'3012-c and the regulations, the higher of the two scores may also be used for the State growth and locally selected measures subcomponents, where such exams are allowable options under Education Law section 3012-c. Any APPR plans in effect for the 2013-14 school year should reflect this local flexibility, as appropriate and allowable under Education Law B'3012-c and the regulations.